vSphere general information (newbie)

[lynxdeb]

Hello guys,

i'm evaluating vSphere 5 (not update1, currently build 469512) to migrate our current XenServer environment to VMware but I did not understand some aspects:

vCenter, ok it should be used to setup Cluster/HA and other things (coming from XenServer there are a lot of new feature, but actually I just need vMotion/FT). I've deployed the Appliance, created a Datacenter then Cluster and add two hosts (two HP DL465G5), imported some VMs (also one converted from Citrix) and vMotion works like a charm (a lot better than XenServer!). What's happen if vCenter (in my case VM) die? HA/vMotion and other feature on the hosts still works? Or I need to have the vCenter alwasy up and running? The currently vCenter Appliance can support newer build of vSphere without update (for example update1 or the other patches)? Or I need to dedicated a physical server to install vCenter Server?

Second thing: patches.. i've seen a lot of patch, and i want to try and update the two hosts to do a bit of experience. In my case (as I read on the documents) esxcli-install should be the right path.. because I cannot install vSphere Update Manager. But for example if I want to install patch ESXi500-201112001 should I need to install also the older patch or are included in the last one?

Third thing: RDM. We want to move to vSphere also to mapping a LUN directly to a VM, is it possibile and still give vMotion/FT capabilities? On our Xen environment we use iSCSI to access LUNs on SAN, but we want to use FC (multipath supported?) now, can be possibile with vSphere?

Last thing: In the current evaluation, i've used NetApp 2240-4 storage and an EMC CX3-20 storage. If I leave connected the CX LUN (that doesn't support ALUA) the esxi hosts will have a LONG boot that should be caused from the second path of EMC that give a lot I/O error. Is it possibile to use this storage on vSphere 5 also if it's not supported (and avoid log boot time)?

Hope someone can reply to my question

Many thanks!

[eeg3 · Accepted solution]

Assuming you have correctly configured HA and it is working, it does not depend on vCenter being available to function. You can test HA functionality by pulling the plug on one of your hosts and seeing if it properly fails over.

You can check the interoperability matrixes for compability between vCenter and hosts, but you should be fine with point update releases.

A physical server is not required for vCenter, and many administrators prefer having vCenter virtual. The Windows version of vCenter has more features currently than the Linux-based appliance. Update Manager is the easiest and most efficient method to apply patches.

vMotion is supported for RDMs in both physical and virtual mode. Virtual mode is supported with FT, but physical mode is not.Fibre Channel is fully supported.

[lynxdeb]

thanks eeg3,

but regarding the patch question, are cumilative patch or i need to install each one?

[eeg3]

The patches are cumulative.

[lynxdeb]

ok, i'll try to patch with the lastest patch before U1, because i've seen there are some bugs on the U1

[Troy_Clavell]

Hello and welcome to the Forums!

...What's happen if vCenter (in my case VM) die? HA/vMotion and other  feature on the hosts still works? Or I need to have the vCenter alwasy  up and running? The currently vCenter Appliance can support newer build  of vSphere without update (for example update1 or the other patches)? Or  I need to dedicated a physical server to install vCenter Server?

vMotion is dependant on vCenter being on-line.  So, if vCenter goes down, there will be no vMotion.  HA is not dependant on vCenter, expect for the initial configuration.  After that, if vCenter would happen to fail, HA would continue to work.

vCenter, in my opinion, should run as a VM.  You can take advantage of feature like HA/DRS.

...because I cannot install vSphere Update Manager

You can install VUM even if using the vCenter Server Linux Appiance. You'll just have to install on a separate machine( another VM would be an ideal choice)

...Third thing: RDM. We want to move to vSphere also to mapping a LUN  directly to a VM, is it possibile and still give vMotion/FT  capabilities?

if you want to use FT, you DRS will be set to disabled by default, but you can manually vMotion the guest.  To use RDMs and FT, the RDM must be virtual.  Storage vMotion is not supported for FT guests

[lynxdeb]

hi troy!

what do you mean for RDMs must be virtual? The LUN will become a datastore for vmware and i present a vmdk to the VM? Or what?

I currently not have a DRS, only a datastore attached to the two hosts (NetApp LUN). Can a currently datastore be converted to a DRS? Is it necessary for my needs?

thanks!

[Troy_Clavell]

virtual compatibility mode

http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.storage.doc_50%2FGUID-4B2479...

see also, VMware Fault Tolerance Requirements and Limitations

[lynxdeb]

ok, i've patched the two hosts to release number 515841, all went ok

now i'm trying to test the hot-add function of vRAM/vCPU

currently i've a guest that runs SLES11SP1 (not the vmware version), VMWare tools installed.. but when I increate the RAM the guest doesn't see it and i need to reboot

is it normal?

[Linjo]

That depends on the OS, not all OS can detect a change in memory and needs a reboot.

// Linjo

[lynxdeb]

i think SLES11 should support it.. or the VMWare SLES11 is customized?

[lynxdeb]

it seems that the module acpi_hotplug wasn't loaded (may be because this VM was imported from Xen)

after a modprobe, new memory is recognized an i can make online via an "echo online" on /proc/sys/memory

vCPU works without load any module

But is it normal that i won't have all memory avaiable? For example, if I assign 1024MB (1GB) to the VM, I see only 956MB, also for 2048MB there are only 1936MB. Is it possibile to have all memory allocated or I need to give a little more to have a full 1/2GB?

Thanks!